State Highway Administration officials showed off a 3.6-mile stretch of restored stream last week in Silver Spring, one example of what they said was a successful environmental stewardship program in areas near the Intercounty Connector.
Contracts B and C of the ICC, the 18.8-mile, east-west highway officials expect to complete by early 2012, will connect the already open section that runs from Interstate 370 to Georgia Avenue with I-95.
The stream, near Bonifant Road and part of the Northwest Branch that runs near the highway, was part of the $370 million in environmental projects that came along with the $2.55 billion ICC. The environmental projects were committed to as part of the ICC’s approval by the environmental regulatory agencies.
The goal, SHA Environmental Manager Rob Shreeve said, was not just to protect the stream, but to improve it.
That meant $6 million in improvements, most of which came by shaving back and reinforcing what were eroded stream banks.
“The project includes all kinds of things you may not consider on the forefront of building a highway,” Shreeve said. “We’re trying to not only fix the stream up, but also help alleviate other problems in the watershed so that all of it contributes to an increased benefit in the watershed.”
Before ICC construction began, the stream’s banks were actively eroding, Shreeve said. A photo of the stream before the restoration project showed banks that were vertical, eight and nine feet tall and full of exposed tree roots and limbs. The SHA and contractors Environmental Quality Resources shaved the banks back to give them a more natural-looking slope less subject to erosion from powerful surges of storm water. Contractors used trees they removed from the path of the ICC to stabilize the banks.
“In 15 years of this work, I think this is some of the best technology I’ve seen on one of these projects,” said Scott Lowe, who helped design the project with his firm, McCormick Taylor. “Whenever you put in an impervious surface, like the ICC, there’s going to be some environmental damage, but a lot of the protections that were done may never have been done.”
During the Oct. 5 tour, Shreeve and ICC project manager Melinda Peters emphasized the efforts workers went took to protect the forest and wetland areas surrounding the highway.
“A lot of monitoring went into figuring out where the trouble areas were and what techniques were needed,” Shreeve said.
In planning construction access routes, planners weaved around significant trees to avoid root damage or scarring. In wetland areas, contractors laid down pallets to keep heavy trucks and equipment from compacting the soil.
The stream restoration project near Bonifant Road, known as Project NW 160-170, will take about 1,000 tons of sediment out of the stream per year, Shreeve said. The project started in February 2010 and should be completed in March. Contractors had to stop work from April to August so as to not disturb the breeding season for the comely shiner, a minnow-like fish listed as a threatened species in Maryland that lives in the Northwest Branch.
The NW 160-170 project will be the largest stream restoration project in SHA history.
As for the highway, Peters said the SHA still was on track to open Contracts B and C to traffic late this year or early 2012. Contract B, which runs from Georgia Avenue to U.S. 29, is about 96 percent complete. Contract C, which runs from U.S. 29 to I-95, is about 94 percent complete. Peters said both sections require more paving. The SHA and Maryland Transportation Administration, which operates the ICC, expect traffic on the completed section of road to increase once the highway is opened to I-95.
“We don’t have a date set yet because we still have some work that needs to be finished,” Peters said. “We need the weather to continue to cooperate.’’